1. Field of the Invention
This invention relates to solvent based compositions containing a polymeric composition that is a highly functional polymer with a relatively high molecular weight and which is substantially free of gelling. The solvent based compositions of this invention are particularly useful in or as coatings, adhesives, inks, primers, and overprint varnishes.
2. Related Background Art
Solvent based compositions containing various polymeric ingredients are well known. Such compositions have often been used as coating compositions, adhesives, primers, overprint varnishes and the like. However, the characteristics and properties achieved in such applications is highly dependent on the polymeric ingredient. Block copolymers are one such polymeric ingredient.
Block copolymers having an A(BA)n structure are well known. For example, U.S. Pat. No. 5,362,819, the entire disclosure of which is incorporated herein by reference, describes an ABA curable block copolymer with an A block that is an unsaturated polyester, preferably having a mono-, or less desirably a di-, hydroxyl, carboxylic or amine end group, and a B block that is a flexible polymer having a glass transition temperature (Tg) of 0xc2x0 C. or less. The flexible polymers are said to include those prepared from conjugated diene monomers, as well as polyethers or saturated polyester, which are linked to the A block by an ester, amide, urea or urethane group.
U.S. Pat. No. 4,347,339, the entire disclosure of which is incorporated herein by reference, describes a water soluble cationic block copolymer having a first polymer block having amino functional groups, a majority of which are quaternary amino groups, and a second polymer block having amino functional groups, a majority of which are not quaternary amino groups. The polymer blocks may be linked with bridges of other polymers, but are preferably linked by including a functional group such as a chloride or epoxide in the first polymer block that reacts with the amino functional groups of the second polymer block.
U.S. Pat. No. 4,851,474, the entire disclosure of which is incorporated herein by reference, describes a block copolymer comprising at least one polyester block and an elastomeric polymer block such as a polymer of one or more conjugated dienes. The elastomeric block is functionalized to incorporate only terminal functional groups, i.e., no more than 2 functional groups per polymeric block.
U.S. Pat. No. 5,008,334, the entire disclosure of which is incorporated herein by reference, describes resins containing an ABA block copolymer having an A block which is a reaction product of a diol and one or more diepoxides and a B block of an epoxy-capped, carboxyl-terminated polybutadiene or polybutadiene/acrylonitrile copolymer. Amine resins which are prepared from a resin that is a mixture of (i) the reaction product of a diol and at least one diepoxide and (ii) the ABA block copolymer are used in electrocoating formulations.
U.S. Pat. No. 5,314,954, the entire disclosure of which is incorporated herein by reference, describes aromatic polyester-polystyrene block copolymers produced by the polycondensation of styrene polymers having terminal functional groups, e.g. hydroxy, amino or carboxyl groups, with an excess of aromatic dicarboxylic acid dihalides and then subjecting the resulting condensation product to interfacial polymerization with aromatic dihydroxy compounds. These aromatic polyester-polystyrene block copolymers are said to have a minimum of uncopolymerized styrene and to be useful for the preparation of optical instruments.
Polyester block copolymers that provide an elastic yarn having a high elastic recovery and a high heat resistance are disclosed by U.S. Pat. No. 5,384,184, the entire disclosure of which is incorporated herein by reference. The polyester block copolymer comprises (A) 30 to 90% by weight of polyester segments comprising a benzenedicarboxylic acid as the main acid component and a diol having 5 to 12 carbon atoms between the hydroxyl groups as the main glycol component and (B) 70 to 10% by weight of polyester segments comprising an aromatic dicarboxylic acid as the main acid component and ethylene glycol, trimethylene glycol, tetramethylene glycol or 1,4-cyclohexane dimethanol as the main glycol component.
U.S. Pat. No. 5,496,876, the entire disclosure of which is incorporated herein by reference, describes a polyetheramide block copolymer constituted by the copolycondensation of polyamide polymers having reactive end groups with polyether sequences having reactive end groups. These polyetheramide block copolymers are blended with a styrene/diene copolymer to form thermoplastic polymeric compositions.
U.S. Pat. No. 4,180,528, the entire disclosure of which is incorporated herein by reference, describes an ABA type block copolymer having an A block that is an addition polymer and a B block that is a linear saturated polyester. The A block and B block are joined by addition polymerization.
European Patent Application Publication No. 0687690/A, the entire disclosure of which is incorporated herein by reference, describes a high temperature polymerization process to produce terminally unsaturated oligomers having relatively low molecular weights. It is further disclosed that the terminally unsaturated oligomers having a carboxylic acid group can be reacted with polyfunctional alcohols having two or more alcohol functionalities to form polyesters. There is, however, no disclosure of terminally unsaturated oligomers having relatively high functionality.
A solvent based composition containing at least one polymeric composition that is highly functional, preferably having high acid functionality, as well as a high molecular weight, but which does not readily gel would be highly desirable.
This invention is related to solvent based compositions comprising (i) a non-aqueous solvent and (ii) a polymeric composition comprising the reaction product of an A polymer which is an addition polymer having 3.5 or more reactive functional groups per polymer chain and a B polymer having about 2 to about 3 functional groups per polymer chain that are co-reactive with the reactive functional groups of the A polymer. Preferably, substantially all of the co-reactive functional groups of the B polymer are co-reacted. More, preferably, the reactive functional groups of the A polymer are condensation reactive functional groups.
Generally, the molar ratio of A polymer to B polymer is about 3:1 to about 2:1.7. Preferably when the B polymer is difunctional then the molar ratio of the A polymer to B polymer, based on the number average molecular weight (Mn) of the two polymers, is about 2:1 to about 2:1.7. When the B polymer is trifunctional then the preferable molar ratio of the A polymer to B polymer is about 3:1.
The condensation-reactive functional group is preferably selected from the group consisting of carboxyl, hydroxyl, epoxy, isocyanato, carboxyl anhydride, sulfo, esterified oxycarbonyl or amino. In a preferred embodiment, the A polymer has 3.5 or more carboxylic acid functional groups per polymer chain. Most preferably, this A polymer is a low molecular weight styrene/acrylic acid/xcex1-methylstyrene polymer.
In another preferred embodiment, the A polymer has 3.5 or more hydroxyl functional groups per polymer chain. In this case, the A polymer is most preferably a low molecular weight styrene/2-ethylhexyl acrylate/2-hydroxyethyl methacrylate polymer.
Preferably, the B polymer is a condensation polymer selected from the group consisting of polyamide, polyester, epoxy, polyurethane, polyorganosiloxane and poly(ether). It is also preferable that the co-reactive functional groups of the B polymer are hydroxyl, epoxy, oxazolinyl or amino.
The polymeric compositions used in the solvent based compositions of this invention are high functional polymers with a relatively high molecular weight that are unexpectedly free of gelling or gel particles. Such polymeric compositions have a broad molecular weight distribution which enhances their utility and performance characteristics. The solvent based compositions of this invention may be employed as coatings, adhesives, inks, primers, overprint varnishes and the like.
The solvent based composition of the present invention is an admixture of at least one component comprising (i) at least one non-aqueous solvent and (ii) at least one polymeric composition comprising the reaction product of an A polymer which is an addition polymer having 3.5 or more reactive functional groups per polymer chain and a B polymer having about 2 to about 3 functional groups per polymer chain that are co-reactive with the reactive functional groups of the A polymer.
The term xe2x80x9csolvent basedxe2x80x9d refers to the mixing of at least one substantially non-gelled polymeric composition as described herein with at least one non-aqueous solvent. The polymeric composition preferably is able to dissolve in the solvent. However, mixtures wherein partial dissolving occurs are included in the present invention. Further, polymeric compositions which do not significantly dissolve in the solvent are included in the present invention. Mixtures are also included in the present invention wherein one or more of the polymeric compositions are added in an amount beyond its solubility.
The polymeric composition employed herein is described in copending U.S. patent application Ser. No. 08/967,848, filed Nov. 12, 1997 entitled xe2x80x9cPolymeric Compositions, and the Preparation and Use Thereofxe2x80x9d, the disclosure of which is incorporated by reference herein.
The A polymer of the polymeric composition employed in this invention is an addition polymer having 3.5 or more reactive functional groups per polymer. The preparation of functionalized addition polymers is well known to those skilled in the art.
Preferably, the reactive functional groups of the A polymer are condensation reactive functional groups. Preferred condensation-reactive functional groups include carboxyl, hydroxyl, epoxy, isocyanato, carboxyl anhydride, sulfo, esterified oxycarbonyl or amino. Carboxyl and hydroxyl functional groups are most preferred. Carboxyl anhydride means a divalent functional group represented by xe2x80x94C(xe2x95x90O)OC(xe2x95x90O)xe2x80x94 in which both free valences are bonded or linked to the addition polymer backbone or a single valent radical represented by Rxe2x80x94C(xe2x95x90O)OC(xe2x95x90O)xe2x80x94 wherein R is an alkyl group having 1-30 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms or an alkyaryl group having 7 to 20 carbon atoms. Sulfo is the radical represented by xe2x80x94SO2OH and esterified oxycarbonyl is an group represented by xe2x80x94C(xe2x95x90O)Oxe2x80x94R wherein R has the same meaning as described above, e.g., alkyloxycarbonyl, aryloxycarbonyl, aralkyloxycarbonyl, or alkaryloxycarbonyl.
The addition polymer, which is the product of a chain-growth polymerization reaction, is prepared from ethylenically unsaturated monomers. These compounds are well known and include, for example, C2 to C20 alkenes, C3 to C20 alkadienes, C5 to C20 alkatrienes, C5 to C20 cycloolefins, vinyl substituted aromatics, acrylic or methacrylic acid, C1 to C20 alkyl esters of acrylic acid or methacrylic acid, C6 to C20 aryl esters of acrylic or methacrylic acid, C7 to C20 aralkyl esters of acrylic or methacrylic acid and the like.
More particularly, such ethylenically unsaturated monomers include, without limitation, ethylene, propylene, 1-butene, 2-butene, isobutene, 1-pentene, 2-methyl-2-butene, 1-hexene, 4-methyl-1-pentene, 3,3-dimethyl-1-butene, 2,4,4-trimethyl-1-pentene, 6-ethyl-1-hexene, 1-heptene, 1-octene, 1-decene, 1-dodecene, allene, butadiene, isoprene, chloroprene, 1,5-hexadiene, 1,3,5-hexatriene, divinylacetylene, cyclopentadiene, dicyclopentadiene, norbornene, norbornadiene, methylnorbornene, cyclohexene, styrene, alpha-chlorostyrene, alpha-methylstyrene, allylbenzene, phenylacetylene, 1-phenyl-1,3-butadiene, vinylnaphthalene, 4-methylstyrene, 4-methoxy-3-methylstyrene, 4-chlorostyrene, 3,4-dimethyl-alphamethylstyrene, 3-bromo-4-methyl-alphamethylstyrene, 2,5-dichlorostyrene, 4-fluorostyrene, 3-iodostyrene, 4-cyanostyrene, 4-vinylbenzoic acid, 4-acetoxystyrene, 4-vinyl benzyl alcohol, 3-hydroxystyrene, 1,4-dihydroxystyrene, 3-nitrostyrene, 2-aminostyrene, 4-N,N-dimethylaminostyrene, 4-phenylstyrene, 4-chloro-1-vinylnaphthalene, acrylic acid, methacrylic acid, acrolein, methacrolein, acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, methyl acrylate, methyl methacrylate, norbornenyl acrylate, norbornyl diacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl acrylate, 2-hydroxybutyl methacrylate, allyl alcohol, propoxylated allyl alcohol, ethoxylated allyl alcohol, glycidal acrylate, glycidal methacrylate, 2-phenoxyethyl acrylate, trimethoxysilyloxypropyl acrylate, dicyclopentenyl acrylate, cyclohexyl acrylate, 2-tolyloxyethyl acrylate, N,N-dimethylacrylamide, isopropyl methacrylate, ethyl acrylate, methyl alpha-chloroacrylate, beta-dimethylaminoethyl methacrylate, N-methyl methacrylamide, ethyl methacrylate, 2-ethylhexyl acrylate, neopentyl glycol diacrylate, cyclohexyl methacrylate, hexyl methacrylate, 2-methylcyclohexyl methacrylate, beta-bromoethyl methacrylate, benzyl methacrylate, phenyl methacrylate, neopentyl methacrylate, butyl methacrylate, chloroacrylic acid, methyl chloroacrylic acid, hexyl acrylate, dodecyl acrylate, 3-methyl-1-butyl acrylate, 2-ethoxyethyl acrylate, phenyl acrylate, butoxyethoxyethyl acrylate, 2-methoxyethyl acrylate, isodecyl acrylate, pentaerythritol triacrylate, methoxy poly(ethyleneoxy)12 acrylate, tridecoxy poly(ethyleneoxy)12 acrylate, chloroacrylonitrile, dichloroisopropyl acrylate, ethacrylonitrile, N-phenyl acrylamide, N,N-diethylacrylamide, N-cyclohexyl acrylamide, vinyl chloride, vinylidene chloride, vinylidene cyanide, vinyl fluoride, vinylidene fluoride, trichloroethene, vinyl acetate, vinyl propionate, vinyl benzoate, vinyl benzoate, vinyl butyral, vinyl chloroacetate, isopropenyl acetate, vinyl formate, vinyl methoxyacetate, vinyl caproate, vinyl oleate, vinyl adipate, methyl vinyl ketone, methyl isopropenyl ketone, methyl alpha-chlorovinyl ketone, ethyl vinyl ketone, hydroxymethyl vinyl ketone, chloromethyl vinyl ketone, allylidene diacetate, methyl vinyl ether, isopropyl vinyl ether, butyl vinyl ethers, 2-ethylhexyl vinyl ether, 2-methoxyethyl vinyl ether, 2-chloroethyl vinyl ether, methoxyethoxy ethyl vinyl ether, hydroxyethyl vinyl ether, aminoethyl vinyl ether, alpha-methylvinyl methyl ether, divinyl ether, divinylether of ethylene glycol or diethylene glycol or triethanolamine cyclohexyl vinyl ether, benzyl vinyl ether, phenethyl vinyl ether, cresyl vinyl ether, hydroxyphenyl vinyl ether, chlorophenyl vinyl ether, naphthyl vinyl ether, dimethyl maleate, diethyl maleate, di(2-ethylhexyl) maleate, maleic anhydride, dimethyl fumarate, dipropyl fumarate, diamyl fumarate, vinyl ethyl sulfide, divinyl sulfide, vinyl p-tolyl sulfide, divinyl sulfone, vinyl ethyl sulfone, vinyl ethyl sulfoxide, vinyl sulfonic acid, sodium vinyl sulfonate, vinyl sulfonamide, vinyl benzamide, vinyl pyridine, N-vinyl pyrollidone, N-vinyl carbazole, N-(vinyl benzyl)-pyrrolidine, N-(vinyl benzyl) piperidine, 1-vinyl pyrene, 2 isopropenyl furan, 2-vinyl dibenzofuran, 2-methyl-5-vinyl pyridine, 3-isopropenyl pyridine, 2-vinyl piperidine, 2-vinyl quinoline, 2-vinyl benzoxazole, 4-methyl-5-vinyl thiazole, vinyl thiophene, 2-isopropenyl thiophene, indene, coumarone, 1-chloroethyl vinyl sulfide, vinyl 2-ethoxyethyl sulfide, vinyl phenyl sulfide, vinyl 2-naphthyl sulfide, allyl mercaptan, divinyl sulfoxide, vinyl phenyl sulfoxide, vinyl chlorophenyl sulfoxide, methyl vinyl sulfonate, vinyl sulfoanilide, unblocked and blocked acetoacetoxy functional monomers (e.g., acetoacetoxyethyl methacrylate and acetoacetoxyethyl acrylate), unblocked and blocked meta-tetramethylisocyanate, unblocked and blocked isocyanto ethyl methacrylate and the like.
At least one of the ethylenically unsaturated monomeric units of the addition polymer must have a reactive functional group such as a condensation reactive functional group, preferably a carboxyl group, hydroxyl group, or epoxy group, most preferably a carboxyl group or hydroxyl group. Exemplary acid-functional ethylenically unsaturated monomers include but are not limited to aconitic acid, acrylic acid, beta-carboxymethyl acrylate, cinnamic acid, crotonic acid, fumaric acid, itaconic acid, maleic acid, methacrylic acid, and mixtures thereof. Also suitable are certain monomers that are said to contain so-called xe2x80x9clatentxe2x80x9d acid moieties, such as cyclic anhydrides. Accordingly, a suitable cyclic anhydrides include but are not limited to itaconic anhydrides, maleic anhydride, and mixtures thereof. Monomers of acrylic or methacrylic acid are most preferred. The condensation reactive functional group is preferably a part of the ethylenically unsaturated monomer, although it may, if desired, be added to the addition polymer after formation of the polymer.
Preferably, the addition polymer used as the A polymer is an acrylic copolymer or a styrene/acrylic acid or styrene/(meth)acrylic acid copolymer, more preferably a styrene/xcex1-methylstyrene/acrylic acid copolymer. Generally, the preferred styrene/acrylic acid addition polymer is comprised of from 10 to 90% w/w styrene, and 10 to 90% w/w acrylic acid. The styrene may be replaced or admixed with xcex1-methyl styrene if desired. As used herein xe2x80x9c% w/wxe2x80x9d is percent by weight of the total polymer weight unless stated to the contrary. Another preferred addition polymer used as the A polymer is a hydroxy acrylate or methacrylate copolymer or a styrene/hydroxy acrylate or styrene/hydroxy methacrylate copolymer, more preferably a styrene/hydroxy acrylate (or methacrylate)/acrylate (or methacrylate) copolymer.
Yet another addition polymer that may be employed as the A polymer in the polymeric composition employed in this invention are hyperbranched polymers such as disclosed in copending U.S. Pat. No. 5,986,020 entitled xe2x80x9cProcess for Producing Hyperbranched Polymersxe2x80x9d, the disclosure of which is incorporated by reference herein. Such hyperbranched polymers having terminal ethylenic unsaturation would preferably have 3.5 of more condensation reactive functional groups per hyperbranched polymer.
Typically the addition polymer is a low molecular weight polymer between about 500 to about 50,000 Mn, preferably about 900 to about 3,000 Mn. As noted previously, the condensation-reactive functionality of the addition polymer must be at least 3.5 or greater, and is preferably between about 3.5 and about 20, most preferably between about 3.5 and about 10.
The preparation of addition polymers is well known to those skilled in the art, and includes gas phase polymerization, solution polymerization, batch polymerization, continuous reactor or tube polymerization, suspension polymerization and emulsion polymerization. Methods of preparing such addition polymers are described in U.S. Pat. Nos. 4,413,370, 4,529,787 and 4,546,160, the disclosure of each of which is incorporated by reference herein.
The B polymer of the polymeric compositions employed in this invention has about 2 to about 3 functional groups that are co-reactive with the reactive functional groups of the A polymer. The preferred functional groups of the B polymer include: hydroxyl, carboxyl, epoxy, oxazolinyl and amino groups, although any group that is co-reactive with the reactive functional group of the A polymer is contemplated within the scope of this invention. The B polymer may be an addition polymer or condensation polymer, but preferably is a condensation polymer. The condensation polymer may be a polyamide, polyester, poly(ether), polyurethane or the like. The preparation of condensation polymers, like that of addition polymers, is well known to those skilled in the art. For example, polyesters may be prepared using common techniques of fusion processes with a glycol excess along with a tin catalyst. Polyamides may be readily prepared using a fusion process, without catalysis.
The preparation of polyesters or polyamides generally requires the use of polycarboxylic acids. Exemplary polycarboxylic acids include, without limitation, adipic, azelaic, benzophenone tetracarboxylic dianhydride, 1,4-cyclohexane dicarboxylate, chlorendic anhydride, diner acids, fumaric acid, glutaric acid, hexahydrophthalic anhydride, itaconic acid, isophthalic acid, maleic acid or anhydride, phthalic anhydride, sebacic acid, suberic acid, succinic acid, terephthalic acid, tetrahydrophthalic anhydride, trimellitic anhydride, alkanyl succinic anhydride, 5-sodiosulfoisophthalic acid, or 5-lithiosulfoisophthalic acid. Generally, the preparation of polyester glycols will employ components such as 1,3-butanediol, 1,4-butanediol, cyclohexanedimethanol, diethylene glycol, dipropylene glycol, 2,2-dimethyl-1,3-pentane diol, 2-butyl-2-ethyl-1,3-propane diol, ethylene glycol, propylene glycol, pentaerythritol, trimethylol ethane, trimethylol propane, tris(hydroxy ethyl)isocyanurate, 1,6-hexanediol, 1,5-pentanediol, triethylene glycol, tetraethylene glycol, hydrogenated Bisphenol A, glycerin, 2 methyl-1,3-propane diol or the like.
In the preparation of polyamides, the polyamine functional components typically may be chosen from ethylene diamine, hexamethylene diamine, 2-methyl-1,5 pentane diamine, isophorone diamine, methylene dicyclohexyl amine, trimethyl hexamethylene diamine or the like.
The starting acids are polymerized fatty acids, which are mixtures of monobasic acids (C18), dibasic fatty acids (C36) and trimer or polybasic fatty acids (C54 or higher), dicarboxylic acids including aliphatic, cycloaliphatic, and aromatic dicarboxylic acids such as oxalic, glutaric, malonic, adipic, succinic, sebacic, azelaic, suberic, pimelic, terephthalic, 1,4 or 1,3-cyclohexane, naphthalene, phthalic, isophthalic, dodecanedioic dicarboxylic acids. Preferred dicarboxylic acids are straight chain aliphatic diacids having at least 6 carbon atoms and more preferably 6 to about 22 carbon atoms such as sebacic, dodecanedioic, and azelaic dicarboxylic acids. Mono carboxylic acids may be added to control the molecular weight. Preferred monocarboxylic acids are linear and have 2 to 22 carbon atoms. Most preferred are stearic and oleic acids.
The diamines used in the preparation of the polyamide may be one or more of the known aliphatic, cycloaliphatic or aromatic diamines having from about 2 to about 20 carbon atoms. Preferred are the alkylene diamines such as ethylene diamine, 1,3-diaminopropane, 1,4-diaminobutane, p-xylene diamine, 1,6-hexamethylene diamine, cyclohexyl amine, bis(4-cyclohexylamine)methane, 2,2xe2x80x2-bis(4-cyclohexylamine)propane, polyglycol diamines, isophorone diamine, m-xylene diamine, cyclohexylbis(methylamines), polyoxyalkylenediamine (sold by Huntsman under the trade name Jeffamine), 2-methyl-1,5-pentane diamine, 1,4-bis-(2-aminoethyl)benzene, dimer diamine, polyether diamines, methylpentamethylene diamine, and piperazine. The preferred diamines are straight chained aliphatic diamines of 2 to about 20 carbon atoms, especially ethylene diamine and hexamethylene diamine, and cycloaliphatic diamines, especially 4-4xe2x80x2-methylenebis(cyclohexylamine) and piperazine. Mono amines may be added to control the molecular weight. Preferred mono amines are linear and have 2 to 22 carbon atoms. Most preferred are stearyl and oleyl amines.
The condensation polymers may also include mono functional compounds to control functionality. For example, a mono acid such as benzoic acid, p-tertbutyl benzoic acid, veratic acid, rosin, lauric acid, fatty acids such as those made from soya, linseed, tall and dehydrated castor oils may be employed in the preparation of polyesters while mono amines such as stearyl amine, tallow amine and cyclohexyl amine may be employed in the preparation of polyamides.
Preferred polyamide compositions employ nylon type monomers such as adipic acid and 2-methyl-1,5-pentane diamine or dimer acid based monomers using dimer acid with isophorone diamine. Preferred polyester monomers include isophthalic acids and cyclohexyl dicarboxylates along with common glycols such as 3-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, and cyclohexane dimethylol.
The polymeric compositions used in this invention may be prepared by the polymerization of the previously described A and B polymers at a reaction temperature and for a time sufficient to form the polymeric composition. Preferably the reaction is a step growth polymerization reaction, i.e., a condensation polymerization reaction. Yet another embodiment of this invention is directed to the process of preparing the polymeric composition by reacting an A polymer which is an addition polymer having 3.5 or more reactive functional groups (preferably condensation reactive functional groups) per polymer chain with a B polymer having about 2 to about 3 functional groups per polymer chain that are co-reactive with the reactive functional groups of the A polymer. Preferably the reaction is conducted at a temperature and for a time sufficient to form the polymeric compositions by reacting substantially all the co-reactive functionality on the B polymer. Preferably, when the B polymer is difunctional, then the molar ratio of A polymer blended with the B polymer is about 2:1 to about 2:1.7. When the B polymer is trifunctional, then the molar ratio of A polymer blended with B polymer is preferably about 3:1. The preferred blending ratio when a mixture of difunctional and trifunctional B polymer is employed can be readily ascertained by those skilled in the art.
The temperature and time of the reaction will depend on the A and B polymers. For example, if condensation of A and B is by esterification then the reaction temperature may reach 240xc2x0 C. or higher, while if condensation is through the formation of urethane linkages, then room temperature may be all that is necessary. The reaction temperature of the process for preparing the polymeric compositions is generally between about xe2x88x9250xc2x0 C. to about 300xc2x0 C., preferably from about 150xc2x0 C. to about 240xc2x0 C. The reaction temperature should not exceed the decomposition temperature of either the A polymer or the B polymer. Typically the reaction temperature is maintained from 0.5 to about 6 hours.
If desired, solvents and catalysts may be employed in the preparation of the polymeric composition of this invention. The use of such solvents and catalysts is well known to those of ordinary skill in the art. It is important that the A and B polymers be compatible with each other to provide adequate mixing. If the polymers are not compatible, then solvent or staged addition of the polymers may be employed to overcome this. Solvents that are well known to those skilled in the art are also useful in controlling viscosity and permitting appropriate mixing when high temperatures can not be used. In addition, small amounts of solvent may be used for products of reaction such as xylene to azeotrope off water.
The molecular weight of the polymeric compositions employed in this invention are generally broad. Both high weight average molecular weight (Mw) and z-average molecular weight (Mz) are possible, while the number average molecular weight (Mn) is typically not as high. The polymeric compositions employed in this invention are preferably high molecular weight polymeric compositions prepared from low molecular weight polymers in the substantial absence of gel. Without being bound to the theory, it is believed that the functionality of the reacting polymers is responsible for the absence of gel.
The resulting polymeric compositions used in this invention may take the form of block copolymers, e.g. ABA block copolymers. However, the polymeric compositions of this invention are not restricted to block copolymers, but may result, for example in highly branched or complex polymers that may not be considered block copolymers.
Generally, the weight average molecular weight of the polymeric compositions used in this invention range from about 4,000 to about 250,000, more preferably between about 5,000 to about 50,000 as measured by gel permeation chromatography using polystyrene standards. In addition, the preferred polymeric compositions having acid functionality typically have an acid number between about 40 to about 200. As will be apparent to one of ordinary skill in the art, the glass transition temperature (Tg) of the polymeric compositions can be readily varied by altering the monomeric make up of the A and B polymers. Typically the average Tg is xe2x88x9250xc2x0 C. to 120xc2x0 C., although the end use generally dictates the type of Tg that will be sought.
This invention is related to the preparation of industrially useful solvent based compositions containing substantially non-gelled polymeric compositions as described herein. The polymeric compositions used in this invention are admixed with a solvent or solvent system. Further, the polymeric compositions may be used in conjunction with other components which are miscible or immiscible. The solvent cut compositions of this invention are particularly useful as coatings, overprint varnishes, floor finishes, adhesives, paper inks, primers, film printing inks and film primers.
The solvent based compositions of this invention may be prepared by mixing the above described substantially non-gelled polymeric composition with the desired solvent or solvent system. It is also possible to prepare the solvent based composition by in situ preparation of the substantially non-gelled polymeric composition in the desired solvent or solvent system. The particular loading depends on the polymeric composition and solvent or solvent system used. Generally, the amount of solvent in the solvent based composition is typically in a range between about 5 to about 95 percent weight of the composition, Preferably about 5 to about 60 percent by weight of the composition.
The non-aqueous solvents that are useful in this invention are wide ranging. Exemplary solvents include ketones, such as methyl ethyl ketone, methyl isobutyl ketone, methyl amyl ketone and diisobutyl ketone, esters such as butyl acetate and amyl acetate, aromatics such as toluene, xylenes and higher boiling mixtures of aromatics, aliphatics such as mineral spirits, odorless mineral spirits and VMP naphtha, and glycol ethers such as butyl ether of ethylene glycol and butyl ether of diethylene glycol. The solvent choice is dependent upon the end use and the selection thereof is well known to those of ordinary skill in the art. Significantly, the polymeric compositions employed in the solvent based compositions of this invention tend to have a broader solubility range than just a single A or B polymer type.
The solvent based compositions of this invention may contain additional components, the nature of which will depend on the particular application of the composition. For example, the inventive compositions may contain cross-linking agents, defoamers, slip additives, colorants, wetting agents, pigments or colorants, waxes and the like. Those of ordinary skill in the art will be able to readily ascertain such additional components for use in the solvent based compositions of this invention depending on the application thereof, e.g. coating, adhesive, ink, primer and the like.